Beginning at 2nd level, Wardens can seek out and train one animal companion who will travel with them and obey them unconditionally. Such a companion is limited to 2+2 HD initially, and thereafter gains one HD every time the animal’s master gains a level, to a max of 6HD. Typical companions include dogs, wolves, or wild cats such as the lynx or bobcat. The warden can use their companion’s heightened senses to their advantage and can train them to perform certain skills. Choose 1d3 skills initially and add one per level from the following list:

Come – Return even over great distances to a special call

Stay – Stay in place and defend if attacked, but do not challenge

Fetch – Fetch a specific object on command, or a random one if not specified

The warden uses the same saves and attack matrix as fighters, so you can use the tables found in the Labyrinth Lord rules. Allowed armor is leather, Elvish chain or magical – basically any lightweight armor, so there is some room for the DM to house-rule here. You should have two pages (three if you count the license page). My intent was not to create an outdoor thief type of class, but I think you are right that the warden works as that with the light armor and stealth rules. I’ve been considering adding a rule allowing the warden to detect, set or disarm snares and traps, this would also fit with the thief aspect. Thanks for the comments!